Issue 1: Rough idling and loss of power

The Investigation:

Mercedes rough idling

  • As you can see from the stat sheet, the Mercedes is experiencing rough idling and a loss of power

  • This is a common issue that points towards replacing the air mass sensor or ignition coil
  • However, on this particular model replacing these parts may not always cure the fault
  • Circled to the right is the air breather hose, this is prone to splitting but will not be visible unless the air filter housing is removed
  • If split, the symptoms above will occur as there is an air/fuel ratio imbalance
  • To rectify the situation the hosing will need to be replaced. As the air pressure passing through the hose is very high, repairs to the hose are unlikely to be a permanent fix


When investigating any faults, it is important that all aspects of the system are checked! Failure to do so can result in mis-diagnosis and high return rates!

Cambiare Tips and Tricks Issue 1 PDF